virttest.staging.utils_memory: Add utils_memory in virttest staging

This file is just the same as autotest/client/shared. It can be drop
when the utils_memory in autotest package.

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
Update memory related calls in scripts

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
Add virttest.staging.utils_cgroup

Add a new virttest.staging namespace that will hold
libraries whose ultimate destination is autotest.

Add back utils_cgroup to that namespace, and keep
both files in sync until newer versions of autotest
shipping this file will be widely available.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
cgroup: Add CgconfigService class

In order to make it more convenient to start/stop
the service cgconfig, create a specialized class,
built on top of the service API.

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>